1388517221 has 8 divisors (see below), whose sum is σ = 1708944384. Its totient is φ = 1098606960.

The previous prime is 1388517181. The next prime is 1388517223. The reversal of 1388517221 is 1227158831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1388517221 - 2⁶ = 1388517157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1388517223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7629125 + ... + 7629306.

It is an arithmetic number, because the mean of its divisors is an integer number (213618048).

Almost surely, 2^1388517221 is an apocalyptic number.

It is an amenable number.

1388517221 is a deficient number, since it is larger than the sum of its proper divisors (320427163).

1388517221 is a wasteful number, since it uses less digits than its factorization.

1388517221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15258451.

The product of its digits is 26880, while the sum is 38.

The square root of 1388517221 is about 37262.8128433697. The cubic root of 1388517221 is about 1115.6220518990.

The spelling of 1388517221 in words is "one billion, three hundred eighty-eight million, five hundred seventeen thousand, two hundred twenty-one".